 # 1.5gm of a monobasic acid when disslved in 150g of water lowers Frezing pt by 0.165 degrees celsius.0.5g of same acid when titrated,after dissolution in water, requires 37.5ml of N/10 alkali.Calculate degree of dissociation of acid(If Kf of water is 1.86) 11 years ago

Dear student,

Freezing point depression can be calculated using the Clausius-Clapeyron equation and Raoult's law. In a dilute ideal solution the freezing point is:

Freezing Pointtotal = Freezing Pointsolvent - ΔTf

where ΔTf = molality * Kf * i

Kf = cryoscopic constant (1.86°C kg/mol for the freezing point of water)

i = Van't Hoff factor

All the best.

Win exciting gifts by answering the questions on Discussion Forum. So help discuss any query on askiitians forum and become an Elite Expert League askiitian.

Sagar Singh

B.Tech, IIT Delhi

3 years ago
∆Tb=(W2 *1000)/(Mw2  × W1)
0.168=(1.86 X 1000)/(M X 100)
M = 11 0.71

N1 xV1   = Nx V
15.1/10 =(0.2×1000)/M.M   (equivalent)
= 132.45
i= 132.45× 110.71 = 1+ a            HX= H+ X-
alpha= 19.6